High Performance ATM Network Simulators

Two high-performance ATM network simulators, S1M+ and ATMSIM, are designed. They are based on the simulator SIM but they have more advanced properties. Fürst, both SIM+ and ATMSIM support differentiated quality of service (QoS); Second, both of them have the cell validity checking, flow control and congestion control mechanisms; Finally ATMSIM supports both per VC QoS and high switch throughput by using two queuing levels, hence two schedulers. In the first queuing level, we designed a Three-phased Weighted Fairing Queuing (TWFQ) algorithm. TWFQ consists of three time phases. At each phase, a dedicated fair queuing server Weighted Fair Queuing based on Flow timestamp is used. In the second queuing level, a Worst-case Longest Port First (WLPF) algorithm is designed. WLPF can provide admitted connection's QoS under hot-spot traffic. To best satisfy real-time traffic QoS, Prioritized Longest Port First (PLPF) is also designed. A number of simulations fiirther prove that the two simulators with the designed algorithms can obtain better performance than the original simulator SIM.